Apparatus for toasting bread, etc.



June 2, 1936. M. H. GRAHAM APPARATUS FOR TOASTING BREAD, ETC

Filed Nov. 13, 1951 5 sheets-sheet 1 June 2, 1936:. IM, H GRAHAM 2,042,595

APPARATUS FOR TOASTING BREAD, ETC

vJune 2,- 1936. M. n. GRAHAM 2,042,595

APPARATUS FOR TOASTINGBREAD, ETC

June 2, 1936. M H, :du-lxlvlv APPARATUS FOR TOASTING BRAD, ETC

Filed NOV, l, 1931 5 Sheets-Sheet 4 June 2, 1936. M. H. GRAHAM APPARATUS FOR TOASTING BREAD, ETC

Filed Nov. 15, 1931 5 sheets-sheet 5 Patented June 2, 1936 UNITED STATES PATENT OFFICE :Mam APPARATUS Foa 'roAsrmG naam, Ero.

murinonhmsamurnk. man. l Application Number 1s, 1931, sur No. 514,694 p s clam. (cl. zia-19) Broadly considered, this invention relates to an improved process of and apparatus for cooking substances adapted to absorb and contain a varying amount of moistureibut particularly, the invention is directed to a process and apparatus for toasting bread and baking wames. 'Ihe term cooking is herein used in a broad sense to includethe various diierent kinds of cooking operations; such as the above noted toasting and baking actions, and others which essentially decrease the moisture content or percentage of moisture contained in the article subjected to heat.

Generally stated, the invention consists of the novel operations, co-ordination of operations, devices, combinations of devices and arrangement of parts hereinafter described and dened in the claims.

In the toasting oi bread and baking of wa!- iies, there has hitherto been provided various different kinds of apparatus equipped with timed means for rendering the heat radiators (usually electrical heating elements) inactive on the substance being cooked. Such timed apparatus operates according to predetermined setting of clock mechanism or the like to render the heat inactive on the substance being cooked at the termination of a deiinite interval of time and regardless of the conditionvor the extent to which the substance has been toasted, baked or otherwise cooked. In the toasting of bread, for example, the apparatus when once set, would act on a piece of bread as long as it would upon a damp or moist piece of bread, and i1' any account was taken of the different lengths of time required to properly toast the bread, the time interval would have to be estimated and the timing mechanism reset so as to approach as nearly Vas possible the toasting operation desired. Such operations are not only inconvenient but never accurate nor certain of accomplishing the desired result.

In the use of these timed toasters, diner.- ent operations have been utilized to render the cooking or toasting operation inactive on the toast, to wit: (a) by cutting off the current supply to the electrical heating elements or radiators (b) by moving the toast out of the zone o! action of the electrical heating elements or radiators; (c) by moving the electrical heating elements or radiators away from the toast; and i(d) by combining two or more of the above noted actions, a, b, and c.

My invention makes a radical departure from the above noted older method and apparatus for I tion of the bread or substance, thereby utilizing controlling toasting of bread,baking ot wafiles and other analogous cooking actions, in that it substance; and that by using van electric circuit, 10,

arranged to include a part of the substance being cooked, and in said circuit, a device that is responsive to varying current dow, (herein designated as a current-measuring device), substantially the exact condition to which the sub- 15 stance has been toasted, baked or otherwise cooked may be determined and the cooking action terminated. The term current-measuring device is used in the sense. that the said device is sensitive to and/or determines when the current has reached a certain ow.

In experiments carried out to date, I have found that the best results can be obtained by. an arrangement wherein the cooking action is terminated when the current flow in the circuit is decreased to a predetermined extent by the increased resistance in the circuit, due to the de'- creasing moisture content in the material being cooked or in a portion thereof. I further found, that the best results can be obtained by dividing the electrical controlling circuit by means such as electrodes insertable into' the bread or material being cooked, in such manner that the current will iiow through onlya small interior porsubstance, required to cook the substance to a l predetermined desired condition. In tle toasting of a relatively dry piece of bread, ior example, the heat will be applied to the bread for 'a' shorter interval of time than it will to a relatively moist piece of bread, but the resulting toast in both instances will be toasted to a pre- 55 determined condition, the condition being the same in bothinstances.

The scope of utility of the generic features of the invention has been generally indicated. The invention in the instant case is, however, particularly directed to an improved automatic toaster and, as designed for this purpose, the apparatus includes various highly important novel features, which especially adapt the apparatus for the purpose of toasting bread, but some of which features will be found useful in connection with wale bakers and the like.

In the accompanying drawings which illustrate the invention especially designed for the toasting of bread, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. i is a horizontal section taken through the complete toaster on the line I-I of Fig. 2;

Fig. 2 is a front to rear vertical section taken through the toaster on the line 2-2 of Fig. 1;

Fig. 3 is a transverse vertical section taken through the toaster on the line 3-3 of Fig. 2;

Fig. 4 is a transverse vertical section taken through the toaster on the line t--d of Fig. 2;

Fig. 5 is a transverse vertical section taken through the toaster on the line 5 5 of Fig. 2;

Fig'. 5 is a fragmentary perspective showing a part of the casing and particularly illustrating the latch trip and trip-actuating mechanism;

Fig. '7 is a fragmentary detail taken in horizon-- tal section approximately on the iine '|-'I of Fis. 6;

Fig. 8 is a diagrammatic view illustrating the electric Acircuits of the improved toaster;

Fig. 9 is a view corresponding to Fig. 3, but illustrating a modified construction;

Fig, 10 is a Vertical front to rear section taken on the line Iii- I0 of Fig. 9, some parts being broken away and some 'parts being removed;

Fig. 11 is a view corresponding to Fig. 4 but illustrating a modification of some of the elements;

Fig. 12 is a view corresponding to Fig. 3, but illustrating a modification of some of the elements;

Fig. 13 is a fragmentary vertical section taken approximately on the line I3 |3 of Fig. 11-;

Fig. 14 is avview corresponding to Figs. 3 and creased current ilow is utilized to control the toasting of bread.

The toaster illustrated in Figs. 1 to 8, inclusive, will first be described. 'I'he rectangular outer shell or casing II of the toaster is'preferably a thin sheet metal structure mounted on a sheet metal or other suitable base I2 and provided in its top with a large rectangular opening I 3 through which the bread slice y may be in. serted intothe toaster and through which the toast may be ejected therefrom.

Mounted within the casing I I, but spaced from the side walls thereof and secured on the base I2 is a rectangular inner shell preferably of sheet metal and which affords an oven I4 into which the bread to be toasted is inserted through the opening I3. suitably mounted within the oven I4 adjacent but spaced from the side walls thereof are electrical heating elements or heat radiators II.

Secured to the top of the oven and depending therefrom on each side of the opening I3 are ejector guide rods I6 and mounted to slide vertically on these guide rods is a bread carrier or toast-ejector I1 which, as shown, is of skeleton form and comprises a plurality of short cross bars secured to a common rod II. The ejector rod I'I at one end, to wit: as shown, at its front end, 10 is rigidly secured to and supported in a horizontal position by a carrying head I8 mounted and guided for vertical movements and, as shown, this carrier head I8 is in the form of an upright iiat bar having laterally projecting lugs mounted to slide on an ejector guide post or rod I 9 secured at its lower end to the base I2 and` at its upper endto the top of the casing. Preferably, the head-forming bar I 8 is provided with anti-friction rollers 20, see Figs. 2, 5, and 6, that engage 20 the post I9. On one side, head barv I8 is-provided with a projecting latch lug 2| bevelled on its under side. i

For co-operation with the latch lug 2| to hold the ejector down when depressed, there is pro- 25 vided an ejector latch in the form of a springpressed latch bolt 22, see particularly Figs. 5 and 6, that automatically engages over said lug '.ii when the ejector is pressed downward. This latch bolt 22 is shown as mounted in a small twopronged bracket 23, which in turn is secured to a larger bracket 24 rigidly applied to one side of the casing II. These parts just described and certain other co-operating parts are mounted in thespace between the casing andthe oven, pref- 3- erably at the front portion thereof. The outer end of latch bolt 22 is connected to the depending arm oi' a latch trip shown as in the form` of a small bell-crank 25, pivoted to a lug on the bracket 24. For manual release, this bell-crank 40 is shown as provided with a trip arm 28 that projects outward through a slot 21 in one side of the casing I I, as best shown in Figs. 5 and 6.

For setting the ejector in a depressed position and for starting the toasting action, there is pro- 45 vided a master lever 28, shown as pivoted to lugs on the rear walll of the casing and extended along one side of the casing and out through an opening in the front end of the casing where its free end maybe readily engaged and depressed. 50 This lever 23 has a depending arm 29 that is connected by a link 30 to the depending arm of a bell-crank 3| pivoted to the base I2. Arm 3| is connected to one end oi.' a quite strong tension spring 32, the front end of which is anchored 55 to the base I2. The upper arm of the bellcrank 3| has a wide end shown as covered with an insulating material 33 such as vulcanized wood ber, best shown In Figs. 2 and 3. This bell- Vcrank, as will presently be noted, lacts as an 60 electrode projector.

The electrodes just referred to in the form illustrated in Figs. 1 to 8, inclusive, are in the form of small sharp pointed pins 34 mounted in supporting blocks 35 insulated from but secured 65 to the depending free ends of light spring-acting hanger bars 35, the upper ends of which are secured to the top of the oven I4, one just inside of each heating element or radiator I5. At their lower ends, electrodes 34 are provided with heads 70 35 that are arranged to be engaged and pressed upward by the insulated face 33 of bell-crank 3|. Springs 3'| interposed between the blocks 35 and heads 36 normally hold the electrodes pressed downward as far as permitted by small collars 38 provided on said electrodes. The blocks 35 have upwardly extended gauge plates or portions 39, the upper edges of which are beveled, so that the slice of bread y will readily slide beA tween Vthe same. These gauge plates determine the distance from the disposed faces oi' the bread at which the electrodes 34 will penetrate the bread. It should be noted that as a convenient way of connecting the master lever 28 to the head I8 of the ejector I1, said lever is formed with a laterally offset free end equipped with the projecting stud or nger 28' that engages through an ear I8 of said head bar, as best shown in Figs. 1, 5, and 6.

Carried by the ejector II and projecting upward from opposite sides thereof are bread grippers preferably in the form of leaf-like spring arms. 40, the free upper ends of which'are arranged to frictionally clamp the opposite faces of the bread slice and to perform important functions hereinafter described. In the particular arrangement described, the gripper arms 40 are provided with cam lugs 4I which, when the ejector I1 is moved downward to a certain point hereinafter more particularly noted, will be engaged by cam anges 42 of upright strips 43 that are rigidly secured at their lower ends to the base I2 and at their upper ends to the top of the oven.

slice against upward slipping movement under downward movement of the ejector to set position.

As best shown in diagram view Fig. 8, the

electrical heating elements I are in a supply circuit 44 in which is interposed a normally open electric switch in the form of a circuit maker and breaker including fixed contacts 45 and a movable contact 45. As a convenient way of supplying circuit to the controlcircuit which includes the electrodes 34 and will include the slice of bread when the latter is positioned for toasting, the said electrodes are arranged in a shunt 41 that is connected across the leaves of the main or supply circuit 44. A small and sensitive electro-magnet 48 is interposed in one of the leads of the shunt 41 and is arranged to act upon an element that carries the movable switch contact 48.

The movable contact 46 of the control or master switch (made up of the above noted contacts 45 and 4S) is carried by atrip actuator that is subject to the action of the electro-magnet 48. The trip actuator shown is in the form of a quite heavy type armature 49, to which the contact 46 is secured but from which it is electrically insulated, see particularly Figs. 5, 6, '7, and 8. The electromagnet 48 is supported by a bracket-line projection of .a regulating lever 5I the free end of which projects through a slot 52 in the front of one side of the casing I I and as shown, co-opcrates with graduation marks on the said casing. A rod or long stud 50 pivotally connects the armature 49 to the lever 5I and said lever tothe bracket 24. By reference to Fig. 6, it will be noted that the free upper portion of the armature 49 stands in a position so that when dropped, it will strike the upper'arm of latch-tripping bell-crank 25, depress the same and retract the latch bolt- 22.

' Lever 5I will be held against extended movement inclined position in respect to perpendicular and this for a purpose which will appear in the description of the operation.

As will fully appear in the description of th operation. the armature 48 which can move up- 5 ward far enough to engage contact with contacts 45, will be held in that circuit-closing position by armature 49, if at that time there is sufiiclent current through shunt circuit 41 to cause said magnet to hold said armature against the action of gravity; and hence,vas a further importantfeature, there is provided a trip actuator re-setting device, which when the ejector. withthe bread slice thereon is forced down to its cxtreme position and set for action, will -move the armature 49 to the circuit-closing position just stated.v

This re-setting device in the particular arrangement illustrated, comprises a small vertical re-set rod 52', see Fig. 6, guided for vertical move- 20 ment through a lug` 53 on bracket 24, and at its lower end pivotally but adjustably connected to the long end of a small re-set lever 54 plvoted to a lug '55, on the base I2. The short end oil this lever 54 stands in a position to be engaged by the 25 lower end of ejector head bar I8 when the ejectorA is pressed to its extreme lowermcst position. Here attention is called to the fact that when said bar I8 is pressed down to its extreme position, upper end of rod 52a will engage trip-acting arma- 30 ture 49 and move the same to the circuit-closing position stated. Here, however, it is important to. note that when head bar i 8 is pressed down to its extreme lowermost position. as just stated,

. latch lug 2I on said bar I8 will be considerably 35 Operation The operation of thedevice illustrated in Figs. 1 45 to 8, inclusive, quite briey summarized is as follows: Normally, that is, when the toaster is empty and idle, the master lever 28 will be in its uppermost position, under tension from spring 32; the

ejector I1 will be in its raised orfuppermost posi- 50 tion; the latch trip-actuating armature 48 will be dropped onto the upper arm of trip lever the pointed electrodes 34 will be dropped down below the upper surface of the ejector I1; and the trip switch -46 will then be open so that the cur- 55 rent to the heating elements or radiators I5 will be cut off and magnet 48 will be de-energiz'ed. Also in the normal or raised position of the ejector i1, the bread grapples or gripping ngers 48 will be carried to positions in which their cam lugs 4I 60 will be above the cam anges 42 and at such time, the two fingers 40 will be sprung apart far enough to permit ready insertion of the bread slice y between the same-and onto the ejector I 1.

When a slice of bread is to be toasted, it will,

by the operator to start the toaster into action 7Q` is to press the master lever as far as it will go. 'Ihe operations that take place when lever 28 is forced down to its lowest position as just stated are as follows: y

The ejector I1, of course, commences its downward movement .simultaneously with the downward movement of lever 28 and continuessuch movement to its extreme lowermost position. Under the downward movement of lthe ejector, but before any of the other operations hereinafter noted have taken place, the cam flanges 42 acting on the yielding grippers 40 press the same against the bread slice y, causing the same to grip and hold the breadV with sufllcient friction to prevent lifting of the bread from the ejector when a little later on the pointed electrodes 34 are forced in the bread. A little further downward movement of the ejector I1 after the bread grippers 4I) have been closed against the bread slice, forces the lower portion of the bread slice between the gauge plates 89, thereby positioning the electrodes 84 to pierce the bread close to its exposed outer surface. Under still a little further downward movement of the ejector I1, bell-crank 8i, acting on the lower end heads of electrodes 84, force the pointed upper ends of the electrodes upward and above the ejector I1 and through the bread, substantially as shown in. Fig. 3. This engagement of the electrodes with Ythe bread closes the circuit through the bread at that point with a resistance that will be greater or less,.depending'on the amount of moisture in the bread, but which, with the kind of bread used Vi'or toast, regardless of the amount of moisture therein, will have an electrical conductivity. sufiicient to permit a flow of electricity through the magnet 48, when an instant later the switch 45-48 is closed.'

The ilnal and extreme part of the downward movement of ejector I1 causes the lower Aend of its head bar I8 to engage the short end oi re-set lever 54, thereby moving rod 52 upward and causing the latter to lift the armature 49 far enough to close switch 45-46; and instantly, upon thus closing of switch 45-46 magnet 48 becomes energized and acting cn armature 49, will hold said switch closed and maintain the proper toasting current through the electrical heating elements I5 until a time presently to be noted. Upon release of lever 48 from its' extreme lower position, ejector I1 makes a slight upward movement until lug 2| engages latch 22 by which latter further upward or return movement, under the tension of spring 82, is interrupted by said latch; but this movement, as already noted, permits rod 52n to drop below the upper arm of trip bellcrank 25 so that it will not interfere with the tripping action of. the armature presently to be noted. l

When the switch 45--48 is closed and the ejector latch is down in its lower portion, as above stated, the current from the main circuit will now through the electrical heating elements and continue the toasting action of the bread until by the evaporation oi' moisture incident to the toasting action, the current ilow through the bread between electrodes 84 is so decreased by the increasing resistance in the bread that the amount of current permitted to flow through the shunt `41 will not keep magnet 48 energized with suillcient force to hold armature 49 from dropping under the action of gravity and thereby opening switch 45-46. When this weakening of the current, through magnet 48 to the extent that armature 48 is released, takes place, said armature will drop by gravity against the upper arm of bell-crank 25, thereby retracting latch bolt 22 and permitting the ejector I1 and levez- 28 to be quickly thrown to uppermost position under the action of spring 32. Initial movement of armature 48 from its raised position, of course, opens switch 45-46 and immediately cuts oi'f current ilow through the electrical heating elements or radiators Il.

From the above it is'evident that, as already stated, in the introduction of the specification,

the length of time that the bread will be sub- 5 be arranged to produce lightly cooked or very l5 crispl toast. With the particular device illustrated, the above adjustment is accomplished by tilting the lever 5i so as to set armature 49 at vvarious differentv angles in respect to a vertical when in circuit-closing. position and subject to 29 electro-magnet 4B. It is evident that if armature 49 be set near a vertical position, grae/ity will exert'a much less force tending to drop said armature, than it will if said armature be set at a greaterv angle to a vertical' than in a 25 horizontal position. Otherwise stated, the further down lever 5I is turned and the more nearly approaching a horizontal armature 49 -is set, the lighter will be the toasting action, and con- I versely, the more nearly vertical positions said 3') lever and armature are set, more crisp will be the toasting action.

When latch 22 is retracted and the ejector I1 by spring 82 is quickly thrown upward to its normal position, the toast will be well projected out through the opening I8 so that it can be engaged by the fingers and lifted out of the toaster,

Obviously, by depression of lever 28, the ejector I1 should be thrown down to its lowest position, when n o bread slice is in the toaster to complete the shunt circuit 41, latch 22 will operate and armature 49 will be moved upward to close switch -46 just as would be the vcase if a slice oi bread were placed in the toaster; but in this case, shunt circuit will not be closed land the 45 magnet 48 will not be energized and hence, when pressure is released fromlever 28 so as to permit head bar I8 to move its lug 2| up against latch 22, armature 49 will be released and will drop onto trip lever 25, causing latch 22 to be 50 released and the mechanism restored to normal position inthe s ame manner as when the toasting operation has been completed. lIf at any time it should be desirable to trip the ejector,

cut oil the current and restore the parts to nor-fl mal positions, in the midst oi' or before the completion ot a toasting operation, all that is necessary to accomplish that result would be to press upward on the projecting arm 28 of bell-crank- 25, thereby releasing the latch 22.

In the modication illustrated in Figs.'9 and 10, the parts may be assumed to besubstantially as heretofore described, except that the electrodes 56 for the shunt circuit are xarranged to contact with the sides oi' the bread slice y 65 and are carried by the upper ends of. levers 51 intermediately pivoted at 58 to an insulating section i2 of base I2, and the lower ends of these levers 51 are connected to coiled spring 59 to the base I2. The springs 59, as shown, are made up oi' coiled sections connected by links 60 of insulating material. The rollers 51'l on ejector I1 operate on offset intermediate portions of levers 51 to move the electrodes 56 into contact with the bread when the latter is lowered in position electrode 6I by an insulating sleeve 56.

construction, the

for toasting and move said electrodes out of contact with the bread while the bread is being moved to and from toasting position.

With the arrangement of electrodes shown in Fig. 9, the controlling current is caused to pass completely through from one side to the other of the bread.

The construction illustrated in Figs. 11, 12, and 13 is like that illustrated in Figs. 1 to 8, inclusive, .with the following exceptions: The elecytrodes or pins .35 that correspond to the earlier described electrodes or pins 34 are rigidly secured to the heads 35 that correspond to the earlier described heads 35; and the gripper arms 40 are provided with teeth I0' that get a positive` grip on the bread slice y, which will 'positively pull the bread slice down onto the pins or electrodes 34. Otherwise stated, in-the construction y illustrated in Figs. 1 to 8, inclusive, the electrodes or pins were movable and were forced Aupward into the bread slice while in this latter described pins are relatively stationary and the bread slice is moved downward to cause the electrodes topenetrate the bread.

The construction illustrated in Figs. 14 and 15, except for a modified arrangement of the controlling circuit, may be assumed to be like that illustrated in Figs. 11, -12 and 13, and described in connection with the structure illustrated in Figs. 1 to 8, inclusive. In this arrangement, the electrodes are combined in such a way as to form a single barb which -is forced into the bread slice. As illustrated, said modified arrangement of electrodes includes a small tapered truncated tubular electrode 6l that is set into an insulating plug 62, which in turn is anchored to the cross bracket 63 rigidly secured to the base I2.

Extended through but insulated from the tubular electrode 6| visa small rod-like stem 6i of an electrode 65. This electrode 65 forms a sharp-pointed continuation of the barb made up of the-two electrodes, but is spaced from the The barb formed by the electrodes thu's assembled is very small, to wit: about the size shown in Fig. 1., the size thereof being greatlyexaggerated in Fig. 15. With this arrangement of electrodes when the bread is drawn down under downward movement of the toast ejector or carrier and the positive pulling action of the toothed gripper arms Bil- A02 the barb made up of the electrodes will be forced into the bread up into the bread slice approximately in the plane of the medial line thereof and hence both electrodes will be far from the exposed faces of the bread and not directly subject to the cooking heat.

With the arrangements of electrodes shown in Figs. 1 to 13, inclusive, because of the arrangement of electrodes close to the outer faces of the bread slice, the resistance to the flow of current through the bread between the electrodes, will increase from or substantially from the beginning of the toasting action. With the arrangement of electrodes illustrated in Figs. 14 and 15, the action will differ in the following respects. Under the initial toasting or cooking action, the moisture will be driven from the face surfaces of the bread to the interior thereof and hence at the initial part of the toasting action, the resistance to the ilow of current through that portion of the bread that bridges the insulated space between the electrodes 6l and 65, will rst decrease and thereafter will increase. It will of course be understood that the amount of current flow throughl controlling circuit including 'matically in Fig.

' posed a normally open switch the electrodes 8| and 65 will be very small as compared with the current flowing through the heatingelements, and in fact, will be so small that the heating action produced from the co'ntrolling circuit so far as drying or heating action .5

is concerned, will be negligible.

The fact that 'under some conditions the re-i sistance in the bread being toasted or the article being cooked will, at some time during the cooking operation, decrease with the resulting in- 'crease in ow of current in the controlling circuit, makes possible the use of an arrangement wherein the interrupting of the cooking action 4will be caused to take place when the current flow in the lcontrolling circuit is increased to a predetermined extent, instead of being decreased as in the preferred arrangements illustrated.

Such an arrangement is illustrated diagram-y 16. In this arrangement, Fig. I6, I haveused the electrode assembly best shown 20 in detail in Fig. 15. The current is supplied to the heating coils I5 from lead wires M', in one of which is a manually-operated switch 61 that must be closed when current is to be supplied to the heating coils. 25 The electrodes 6I and 65 are connected in series with electro-magnet 68 by shunt Wires 15S-10. A solenoid 1l is connected across theleads 44' by shunt wires 12 and 13, in which wire 13 is inter- 14 that has an 30 armature 15 subject to electro-magnet 68., Solenoid 1|, when energized, holds toward the left a core 16 that is connected to a trip dog 11.` This trip dog normally holds against rotation -a`member 18 of a clockwork or timed mechanism 19 of 35 any suitable type, but, as shown, the one that is operated by a spring 80. With this arrangement, Fig. 16, when the resistance in the .bread drops say from seven ohms down to four ohms, the flow of current through the high resistance magnet 40 68'will be increased to such an extent that it will act on armature 15 and close switch 14; and this will close the circuit through solenoid 1I, thereupon the resulting movement of the core 18 will cause dog 11 to release elements 18 of the clock- 45 work 19. The reason here for employing the clockwork is to delay the cutting off of the current'through electrical heating coils I5. It has been found that in ordinary toasting action, the y drop in the resistance due to the driving of mois- 50 ture from the surface into the interior of the bread, and the resulting of tripping of the clockwork, will take place at too early a period, that is, before the bread has lbeen properly toasted. Assuming that this tripping would take place about fteen seconds, vthe clockwork would be arranged to run fifteen seconds before it performed its function of actually tripping or eutting olf the supply circuit. The clockwork therefore acts simply as a trip-delaying device. Even with this arrangement, which is somewhat complicated and which may be greatly modified, there is still the advantage that the tripping action would be controlled not by actual time, but by the moisture content at the interior of the toast. of

course, as indicated, the clockwork may be arranged to control the supply circuit or other deas illustrated in the Strite Patents Nos. 1,387,870, issued August 16, 1921, and 1,394,450, issued October 18, 1921, both entitled Bread toasters.

From the foregoing', it is evident that both the apparatus andthe process herein disclosed are capable of wide ranges oi' modification within the scope of the invention herein disclosed and claimed.

This application is filed as a continuation in part oi' my pending application, Serial No. 504,777,

lfiled December 26, 1930 and entitled Automatic toaster.

What I claim is:

1. -In an apparatus for cooking substances that contain a variable amount oi' moisture, an electrical heat radiator, a supply circuit therefor, a normally open switch in said supply circuit, a shunt of relatively high resistance connected across said supply 'circuit and including an electro-magnet and spaced electrodes, said electrodes being ,arranged to contact with the substance being cooked to thereby include said substance in said shunt circuit, and said electro-magnet when fully energized serving to hold said switch in circuit-closing position, but'to automatically permit opening of said switch and supply circuit when the increasing electrical resistance due to decreasing moisture content in the substance has reduced the current iiow through said shunt and electro-magnet to a predetermined point.

2. 'I'he structure deilned in claim 1 in further combination with means for projecting said electrodes into contact with the lsubstance being cooked substantially simultaneou'slvwith closing of the circuit through said shunt and its electromagnet, and fordis-associatingsaid electrodes with the said substances when said electro-magnet is de-energized sufiiciently to release and permit opening of the switch in said supply circuit.

3. In an apparatus for cooking substances that contain a variable amount of moisture, an electrical heat radiator, and automatic electro-magnetic means involving a circuit arranged to include, as a part thereof, the substance being cooked, and automatically operative to render said radiator inactive on said substance, when the increasing electrical resistance due to decreasing moisture content in the substance being cooked has reduced the current now therethrough to a predetermined point, and in which structure the magnetic means includes an electro-'magnet in its circuit, and a trip-acting armature arranged to be held and released by said magnet, a normally open switch controlling the supply o1 current to said electrical heat radiator and arranged to be closed when said amature is held by an electro-magnet and to be opened when said armature is released.

4. In a toaster, the combination with electrical heating elements and a circuit therefor including a normally open switch, of means for closing said switch at will to start the toasting action, of a toast ejector under strain to move in a direction to eject the toast, a latch for holding said toast ejector in retracted position, and means involv latch tripping Ain'g a circuit arranged to' include the positioned toast as a part thereof, and operative to open said switch and cut oil' the current supply to said electrical heating elements. when the increasing electrical resistance due to decreasing moisture content in the toast has reduced the current iiow therethrough to a predetermined point.

5. In a toaster. an oven, `electrical heating elements in said oven, a toast ejector under strain to move and eject the toast, a latch for securing said ejector against toast-electing movement, and means for releasing said latch including a amature and a control circuit, said circuit including an electro-magnet and electrodes arranged to engage thel toast and' cause a portion thereof to form a part of said control circuit, said magnet, when energized to a certain extent serving to hold said 'armature against latch-releasing movement and said switch closed, but arranged to release the same for latch-releasing and switch-opening actions when the increasing electrical resistance due to decreasing moisture content in the toast has reduced the current ilow thrOl-lh said magnet to a predetermined point.

6. The structure deilned in claim 5 in further combination with a master lever connected to move with said toast ejector and operative to set 4the latter in a retracted position subject to said latch, and means operatively connected to said lever operative to engage said electrodes with the toast when said toast ejector 'is moved to said latch-retained position and disengage said electrodes from the toast when said ejector is released for a toast-ejecting action.

7. 'I'he structure denned in claim 5 in further combination with a masterlever connected to move with said toast ejector and operative to set the latter in a retracted position subject to said latch, means operatively connected to said lever operative to engage said electrodes with the toast when said toast ejector is moved to said latchretained position and disengage said electrodes from the toast when said ejector is released for a toast-electing action, and gauge devices en' gageable with the sides of the bread slice and operative to space said electrodes to engage the bread slice at predetermined distances from the exposed surfaces thereof.

8. The structure defined in claim 5in further combination with are-setting device rendered operative by extreme movement of said toast ejector to retracted position and operative to move said armature into aswitch-closing position subject to the magnet of said control circuit.

9. 'I'he structure dened in claim 5 in further combination with a re-setting device rendered operative by extreme movement of said toast ejector to retracted position and operative to move said armature into a switch-closing position subject to the magnet of said control circuit, and a master lever movable with said toast ejector and operative to setthe latter in retracted position subject to said latch.

l MAURICE H. GRAHAM. 

